(CNN) -- Virginia Gov. Bob McDonnell on Tuesday night tried to sell the American public on the virtues of having the GOP in charge of states.
In a speech at the Republican National Convention, McDonnell said that unemployment was lower in states led by Republican governors than in those headed by Democrats.
"In states with Republican governors, the average unemployment rate is a full point lower than in states with Democratic governors. It makes a difference. Republican governors lead seven of the 10 states with the lowest unemployment rates. And 12 of the 15 states that have been ranked 'best for business' have Republican governors."
A quick check of the governors' party affiliations shows 29 states with GOP governors, 20 states with Democratic governors, and one state headed by an independent. According to the Bureau of Labor Statistics' preliminary, seasonally adjusted data for July 2012, 7.84% of the civilian labor in the 29 states with Republican governors were unemployed (6,680,400 out of 85,155,600).
The same data set shows that 8.77% of the 20 states with Democratic governors were unemployed (6,032,500 out of 68,792,500). The national unemployment rate was 8.3%.
The difference between 7.84% and 8.77% isn't a full point, though it is close. However, there's nothing in the data itself to show a causal relation.
It's also worth noting that in 11 of the Republican-led states, the party has had control of the governorship for less than 19 months.
It is true that, according to the July 2012 BLS data, seven of the 10 states with the lowest unemployment rates have Republican governors, led by North Dakota, with 3.0%.:
1) North Dakota (R) 3%
2) Nebraska (R) 4%
3) South Dakota (R) 4.4%
4) Oklahoma (R) 4.9%
5) Vermont (D) 5%
6) Iowa (R) 5.3%
7) New Hampshire (D) 5.4%
8) Wyoming (R) 5.6%
9) Minnesota (D) 5.8%
10) Virginia (R) 5.9%
In four of those Republican-led states (including McDonnell's Virginia), Republicans have held the governorship for less than 19 months. The same is true for two of the three Democrat-led states.
As for the "best for business" claim, a McDonnell spokesman said the governor was referring to "CNBC's America's Top States for Business 2012" list. The criteria include rankings for workforce, quality of life, economy, infrastructure and transportation, access to capital and cost of living. We'll not go deeper into how CNBC arrived at its rankings, or how much governors' actions affected those rankings, but McDonnell's statement that 12 of the list's top 15 states have Republican governors is correct.
In five of those states, Republicans have held the governorship for less than two years. The same was true for Democrats in one state.
Verdict: True, but incomplete.
CNN's Jason Hanna, Julie In and Amy Roberts contributed to this report.